The present invention generally relates to sediment control devices and systems useful for controlling soil erosion and sedimentation, for example resulting from construction activities.
Silt barriers, sandbags and concrete blocks are some of the many devices currently being used to control soil erosion and sedimentation resulting from industrial activities, such as construction projects and the like. Industrial activities such as highway and housing construction projects and the like, disturb and loosen soil, which is then vulnerable to being washed downstream during rains. The cumulative effect of these activities is a build-up of soil and other matter in waterways. This buildup of soil is generally known as sedimentation. Excessive sedimentation in waterways can destroy fish habitats, suffocate trees, clog streams, obstruct storm drains and culverts, pollute waterways, and cause other serious damage to the environment. Other detriments caused by excessive sedimentation include flooding, cost of repairing flood damage, expense of dredging estuaries and lakes, among others.
In addition to sediment loading, other pollutants are also generated from land disturbance associated with construction projects.
The Clean Water Act defines point source pollutants to include storm water discharge from such industrial activities as construction. As a result, an increased number of state environmental regulations have addressed the mitigation of construction site runoff and a variety of new erosion control methods have been proposed and implemented.
Construction activities related to building roads and highways, flood control projects, and land development for residential and commercial growth contribute sediments, organic matter, nutrients, metals, and other types of pollutants to water bodies. It is believed that sediment is the major pollutant associated with construction related activities, representing approximately 4-5% of the nation's sediment load to adjacent and downstream receiving waters.
Conventionally, sandbags have been used to supplemental other soil control measures, such as the installation of silt fencing, catch basins and the like. Conventional sandbags are inexpensive and convenient to install and are often placed adjacent disturbed areas to block sediment from entering drainage areas. Sandbags can also be used to divert flowing water to a stable drainage outlet. The most commonly used bags are untreated burlap sacks available at feed or hardware stores. Such bags are filled with sand to form a sandbag. Sandbag barriers are typically constructed on site by two people. A typical filled sandbag weighs around 30 to 40 pounds and can be dragged or carried by a single person.
Although they are convenient to install, the use of conventional sandbags in, or around construction sites suffers significant drawbacks. For example, the bags regularly burst when run over by machinery or construction vehicles. For obvious reasons, broken sandbags will exacerbate sedimentation problems if not removed promptly. The useful life of a sandbag is estimated to be about 2 weeks on a typical construction site.